{
 "company": "Marathon Petroleum",
 "ticker": "MPC",
 "page": "https://www.moatshark.com/s/mpc",
 "note": "Source: SEC filings via moatshark. Values and changes are estimates; not investment advice.",
 "holders": [
  {
   "manager": "Harris Associates (Oakmark)",
   "moatshark_slug": "harris-associates-oakmark",
   "period": "2026-06-30",
   "portfolio_pct": 0.08,
   "value_usd": 58551242,
   "change": "REDUCE",
   "share_change_pct": -91.8,
   "quarters_held": 6
  },
  {
   "manager": "Matrix Asset Advisors",
   "moatshark_slug": "matrix-asset-advisors",
   "period": "2026-09-30",
   "portfolio_pct": 0.03,
   "value_usd": 337689,
   "change": "HOLD",
   "share_change_pct": 0,
   "quarters_held": 3
  },
  {
   "manager": "Horizon Kinetics",
   "moatshark_slug": "horizon-kinetics",
   "period": "2026-06-30",
   "portfolio_pct": 0.02,
   "value_usd": 1329995,
   "change": "HOLD",
   "share_change_pct": 0,
   "quarters_held": 25
  },
  {
   "manager": "Mairs & Power",
   "moatshark_slug": "mairs-power",
   "period": "2026-06-30",
   "portfolio_pct": 0,
   "value_usd": 355381,
   "change": "HOLD",
   "share_change_pct": 0,
   "quarters_held": 4
  }
 ]
}